Design and analysis of light-weight lattice sandwich cylinders

Sandwich cylinders have good mechanical strength and are relatively light, which results in many applications of these structural materials in aerospace and aviation engineering. Honeycomb or foam sandwich cylinders are quite common nowadays, but stretching dominated lattice sandwich cylinders having a higher specific stiffness and specific strength are rarely reported. The effective properties homogenization theory of lattice materials was used to build analytical models to predict the axial stiffness and effective yield strength of lattice sandwich cylinders. Finite element simulations verified the model validity. The results show that the sandwich cylinders with stretching dominated lattice materials have better mechanical properties than honeycomb sandwich cylinders and can achieve 25% weight loss for the same carrying capacity. Filament winding and twice co-curing processes can be used to make carbon fiber reinforced composite (CFRC) lattice sandwich cylinders. Axial compression experiments were used to measure the stiffness and load capacity of fabricated sandwich cylinders. The experimental results also show that the bearing capacity and stiffness of lattice sandwich cylinders increase to three times that of the grid stiffened cylinders with similar dimension and weight.